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Re: What does C++ say about climate change?

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Jorgen Grahn

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Jun 29, 2019, 10:55:24 AM6/29/19
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On Sat, 2019-06-29, Stefan Ram wrote:
...

Lots of things are more important than C++, but they are still
offtopic here.

/Jorgen

--
// Jorgen Grahn <grahn@ Oo o. . .
\X/ snipabacken.se> O o .

Keith Thompson

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Jun 29, 2019, 5:23:30 PM6/29/19
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r...@zedat.fu-berlin.de (Stefan Ram) writes:
> Subject: Re: What does C++ say about climate change?

Nothing.

> »"Goodbye, " << "Planet!"«
>
> n4800, 28.10.3.4 Member functions [syncstream.osyncstream.members]

In context, it's simply a phrase in contrast to "Hello, World!".

--
Keith Thompson (The_Other_Keith) ks...@mib.org <http://www.ghoti.net/~kst>
Will write code for food.
void Void(void) { Void(); } /* The recursive call of the void */

Chris Vine

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Jun 29, 2019, 5:37:04 PM6/29/19
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On 29 Jun 2019 12:09:08 GMT
r...@zedat.fu-berlin.de (Stefan Ram) wrote:
> »"Goodbye, " << "Planet!"«
>
> n4800, 28.10.3.4 Member functions [syncstream.osyncstream.members]
>
> (It might sound cynical, but when people are driving
> 90 miles an hour down a dead-end road what else is left?)

I think that by mistake you posted to the wrong group. C++ says nothing
about climate change. C++ is a programming language.

Evidence indicates beyond reasonable dispute that global temperatures
are rising, partly because of human intervention. Sea levels are about
2cm higher than 200 years ago. They are about 130 metres higher than
at the end of the last glaciation maximum, mainly because of natural
temperature and climate variation because we are now in an inter-glacial
period of an ice age. Sea levels are still over 200 metres lower than
they were 100 million years ago (a blink of the eye geologically
speaking). 250 million years ago Antartica was forested even though it
was only somewhat further north than now, because the joining of the
North and South American continents had not then occured so
extinguishing trans-global currents. For the larger part of earth's
history there has been no permanent ice on both poles: ice ages such as
the present one are typically unusual (plate techtonics have been a big
driver of climate variation): in earth's history there have been at
least 5 of them. One of them (the Cryogenian) may have produced a
"snowball earth" with ice sheats to the equator.

Carbon dioxide absorption by silicate weathering will in due course
become a threat to bio-diversity (100 to 500 million years ahead) by
reducing carbon dioxide below the level required for the main form of
photosynthesis to occur (but new forms of vegetation will adapt).
Increased solar radiation is a bigger long term threat as nuclear fuel
is slowly expended, which at some point (approx 1 billon years ahead)
will cause thermal runaway and evaporation of the oceans, long before
the sun turns into a red giant. If technology is sufficiently existent
at that time, then it may possibly be averted technologically be
reflecting the radiation back into space. Nothing is likely to defend
when the sun becomes a red giant in some 5 billion years time, and
nothing at all will defend the subsequent extinguishment of solar
radiation.

As Private Fraser would say, "we are all doomed". We are all on your
dead-end road. (The universe is also, by virtue of the 2nd law of
thermodynamics - the universe has an arrow of time.)

Alf P. Steinbach

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Jun 29, 2019, 7:22:08 PM6/29/19
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On 29.06.2019 23:36, Chris Vine wrote:
>[snipped interesting historical overview]
>
> As Private Fraser would say, "we are all doomed". We are all on your
> dead-end road. (The universe is also, by virtue of the 2nd law of
> thermodynamics - the universe has an arrow of time.)

Since we're off-topic and it's, well now it's Sunday already. Since it's
Sunday.

The last parenthetical remark, short as it is, contains a number of errors.

First, the application of a statistical law that applies to inert gases,
to the universe at large, is at best invalid. It's not the case that a
system of more interestingly interacting parts than inert atoms, is
necessarily likely to evolve towards an uninteresting homogeneous state.
Of course it depends on what one means by interesting, but. It's easy to
construct artificial systems, systems with less than totally inert
parts, that evolve in interesting ways without ever going into a
homogeneous state. If such a system is started in an apparently
homogeneous state it can/will evolve away from it, towards complexity.

To wit, the current generally accepted cosmological hypothesis, called
the Big Bang, has it that the universe started in a nearly completely
homogeneous state, and evolved to the interesting complex structure we
see around us.

Sad observation of the kind of science going on: the cosmological
principle is the idea that at a sufficiently large scale the universe is
still homogeneous. But every proposed and at the time accepted scale,
has been contradicted by observations, and this has happened many times.
Every time the idea, alleged fact, is refuted by observations of larger
structures, say roughly once a decade, it's relaunched with just an
adjustment of the scale, and worse, scientists then forget the history.

Secondly, the remark seems to equate increase of entropy with time.

For a sufficiently simple system, like the mentioned inert gas, a time's
arrow causes entropy increase. Necessarily, logically, because the
uninteresting gas-everywhere states are in the zillions compared to
those states that can be identified as not-gas-everywhere, and there's
no structuring process going on. So with a random walk to nearest states
it rapidly gets to gas-everywhere. But even in such a simple system it's
the time's arrow that drives the system evolution, not opposite. They're
not on equal terms, as one can readily see by implementing a simulation.

It pains me that the scientific community is at odds with both logic and
observations about this matter. I think it's like religion, or some
kinds of politics, or war. Everybody adopts or pretends to adopt the
belief that they see that everybody else, in particular authorities, say
they have. And so we had 2000 years of crystal spheres. And now a
hundred years at least of Big Bang and predicted entropic death of the
universe. Happily sooner or later there will be observations that
shatter the current variation of belief, like Tycho Brahe's comet
shattered the crystal spheres (or rather didn't), but as the repetitive
history of the cosmological principle shows, that may not be enough:
with a strong enough social force the theory is just amended.

Cheers!,

- Alf
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